1. Field of the Invention
The present invention relates generally to a row crop header for a forage harvester and, more particularly, is directed to an improved rotary crop severing mechanism for severing the crop as the header advances forwardly over a field of crop planted in spaced apart rows.
2. Description of the Prior Art
A typical forage harvester operating in row planted stalk crops; such as corn, sorghum maize, etc., includes a mobile base unit and a row crop header for gathering the crop from the field. The base unit usually includes a processing mechanism for processing the crop gathered by the header. The header, positioned in front of the processing mechanism, generally includes a plurality of row crop units each having an elongated crop passageway for receiving a respective row of crop, a severing mechanism associated with the passageway of each row unit for severing the stalks a short distance above the ground, and conveying means for conveying the severed crop rearwardly along the passageway to the crop processing mechanism.
Oftentimes during harvest, fine stemmed grasses or grass-like materials are found growing within the rows along with the row crops. These grasses adversely affect the harvest of the row crops in that they tend to wrap around and hair-pin about the operational components of the header causing blockage and damage thereof.
One type of rotary severing mechanism which has been recently employed with the row crop headers includes a pair of upper and lower peripheral overlapping cutting discs that define a severing zone within the passageway for severance of the crop as it enters the passageway. This type of severing mechanism works quite satisfactorily in severing the row crop but does not satisfactorily sever the grasses within the row crop which adversely affects the operation of the header. Some of the grasses tend to slip between the rotary cutting discs and are not severed, the unsevered grasses tending to hair-pin behind the discs interfering with the conveyance of the severed crop stalks rearwardly along the passageway.